1. Field of the Invention
The invention concerns an electromagnetic wave detector, especially to detect and measure the amplitude of an optical wave in a semiconducting material and an image analyzer comprising a detector of this type.
2. Description of the Prior Art
In infrared wave applications, there are two types of detectors known: pyroelectrical detectors which can work at ambient temperature but are slow and detectors with absorption by a type II-VI semiconducting material. These latter detectors are based on the absorption of the wave to be detected by a transition of electrons from the valence band to the conduction band of the semiconducting material. The free electrons thus created are then collected and drained by an electrical circuit. The measurement of the corresponding current enables the measurement of the optical power received by the detector. These devices should therefore consist of semiconducting materials for which the bandgap is smaller than the energy corresponding to the wave to be detected. This fact leads to the use of II-VI semiconducting materials which are presently very difficult to manufacture. Furthermore, it is not possible to make optical guides and a standard detector with one and the same semiconducting material since the guide should be made with materials transparent to the wave to be propagated while a standard detector requires the use of a semiconducting material that absorbs this very same wave. It is therefore not possible, in integrated optics, to make a low-loss guide and a detector on one and the same semiconductor substrate.
The aim of the invention is to propose a detector made of semiconducting materials which can be manufactured by simpler manufacturing techniques and enables the integration of the optical guides and a detector on one and the same substrate.